diff --git a/configure b/configure
index 504f6410274..7dd1fd5bb69 100755
--- a/configure
+++ b/configure
@@ -786,6 +786,7 @@ with_build_libsubdir
 with_system_zlib
 enable_as_accelerator_for
 enable_offload_targets
+enable_offload_defaulted
 enable_gold
 enable_ld
 enable_compressed_debug_sections
@@ -1515,6 +1516,11 @@ Optional Features:
                           enable offloading to devices from comma-separated
                           LIST of TARGET[=DIR]. Use optional path to find
                           offload target compiler during the build
+  --enable-offload-defaulted
+		If enabled, configured but not installed offload compilers and
+		libgomp plugins are silently ignored.  Useful for distribution
+		compilers where those are in separate optional packages.
+
   --enable-gold[=ARG]     build gold [ARG={default,yes,no}]
   --enable-ld[=ARG]       build ld [ARG={default,yes,no}]
   --enable-compressed-debug-sections={all,gas,gold,ld,none}
@@ -2981,6 +2987,14 @@ else
 fi
 
 
+# Check whether --enable-offload-defaulted was given.
+if test "${enable_offload_defaulted+set}" = set; then :
+  enableval=$enable_offload_defaulted; enable_offload_defaulted=$enableval
+else
+  enable_offload_defaulted=
+fi
+
+
 # Handle --enable-gold, --enable-ld.
 # --disable-gold [--enable-ld]
 #     Build only ld.  Default option.
diff --git a/gcc/config.in b/gcc/config.in
index 313c13c8e49..fb88acb3c34 100644
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -2190,6 +2190,12 @@
 #endif
 
 
+/* Define to 1 to if -foffload is defaulted */
+#ifndef USED_FOR_TARGET
+#undef OFFLOAD_DEFAULTED
+#endif
+
+
 /* Define to offload targets, separated by commas. */
 #ifndef USED_FOR_TARGET
 #undef OFFLOAD_TARGETS
diff --git a/gcc/configure b/gcc/configure
index 33eae5451ad..f5bef76ef77 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -8058,6 +8058,12 @@ $as_echo "#define ENABLE_OFFLOADING 0" >>confdefs.h
 
 fi
 
+if test "x$enable_offload_defaulted" = xyes; then
+
+$as_echo "#define OFFLOAD_DEFAULTED 1" >>confdefs.h
+
+fi
+
 
 # Check whether --with-multilib-list was given.
 if test "${with_multilib_list+set}" = set; then :
@@ -19392,7 +19398,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 19395 "configure"
+#line 19401 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -19498,7 +19504,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 19501 "configure"
+#line 19507 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
diff --git a/libgomp/Makefile.in b/libgomp/Makefile.in
index eb868b36704..9685704c355 100644
--- a/libgomp/Makefile.in
+++ b/libgomp/Makefile.in
@@ -16,7 +16,7 @@
 
 # Plugins for offload execution, Makefile.am fragment.
 #
-# Copyright (C) 2014-2020 Free Software Foundation, Inc.
+# Copyright (C) 2014-2021 Free Software Foundation, Inc.
 #
 # Contributed by Mentor Embedded.
 #
diff --git a/libgomp/config.h.in b/libgomp/config.h.in
index 03123dc1e60..e702625ab6e 100644
--- a/libgomp/config.h.in
+++ b/libgomp/config.h.in
@@ -143,6 +143,9 @@
    */
 #undef LT_OBJDIR
 
+/* Define to 1 to if -foffload is defaulted */
+#undef OFFLOAD_DEFAULTED
+
 /* Define to offload plugins, separated by commas. */
 #undef OFFLOAD_PLUGINS
 
diff --git a/libgomp/configure b/libgomp/configure
index 1917d7e273b..6161da579c0 100755
--- a/libgomp/configure
+++ b/libgomp/configure
@@ -14995,6 +14995,12 @@ $as_echo "#define LIBGOMP_OFFLOADED_ONLY 1" >>confdefs.h
 
 fi
 
+if test "x$enable_offload_defaulted" = xyes; then
+
+$as_echo "#define OFFLOAD_DEFAULTED 1" >>confdefs.h
+
+fi
+
 # The cast to long int works around a bug in the HP C Compiler
 # version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
 # declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
diff --git a/libgomp/configure.ac b/libgomp/configure.ac
index c23fe004f1d..7df80a32765 100644
--- a/libgomp/configure.ac
+++ b/libgomp/configure.ac
@@ -221,6 +221,11 @@ if test x$libgomp_offloaded_only = xyes; then
             [Define to 1 if building libgomp for an accelerator-only target.])
 fi
 
+if test "x$enable_offload_defaulted" = xyes; then
+  AC_DEFINE(OFFLOAD_DEFAULTED, 1,
+    [Define to 1 to if -foffload is defaulted])
+fi
+
 AC_CHECK_SIZEOF([void *])
 
 m4_include([plugin/configfrag.ac])
diff --git a/lto-plugin/Makefile.in b/lto-plugin/Makefile.in
index 20611c6b1e6..b33ffed6e48 100644
--- a/lto-plugin/Makefile.in
+++ b/lto-plugin/Makefile.in
@@ -350,8 +350,8 @@ libexecsub_LTLIBRARIES = liblto_plugin.la
 in_gcc_libs = $(foreach lib, $(libexecsub_LTLIBRARIES), $(gcc_build_dir)/$(lib))
 liblto_plugin_la_SOURCES = lto-plugin.c
 # Note that we intentionally override the bindir supplied by ACX_LT_HOST_FLAGS.
-liblto_plugin_la_LDFLAGS = $(AM_LDFLAGS) $(lt_host_flags) -module -avoid-version \
-	-bindir $(libexecsubdir) $(if $(wildcard \
+liblto_plugin_la_LDFLAGS = $(AM_LDFLAGS) $(lt_host_flags) -module \
+	-avoid-version -bindir $(libexecsubdir) $(if $(wildcard \
 	$(libiberty_noasan)),, $(if $(wildcard \
 	$(libiberty_pic)),,-Wc,$(libiberty)))
 # Can be simplified when libiberty becomes a normal convenience library.
diff --git a/lto-plugin/configure b/lto-plugin/configure
index baa84adbb6c..22a4357a58e 100755
--- a/lto-plugin/configure
+++ b/lto-plugin/configure
@@ -8429,23 +8429,25 @@ _LT_EOF
 fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $lt_cv_ld_force_load" >&5
 $as_echo "$lt_cv_ld_force_load" >&6; }
-    case $host_os in
-    rhapsody* | darwin1.[012])
+    # Allow for Darwin 4-7 (macOS 10.0-10.3) although these are not expect to
+    # build without first building modern cctools / linker.
+    case $host_cpu-$host_os in
+    *-rhapsody* | *-darwin1.[012])
       _lt_dar_allow_undefined='${wl}-undefined ${wl}suppress' ;;
-    darwin1.*)
+    *-darwin1.*)
       _lt_dar_allow_undefined='${wl}-flat_namespace ${wl}-undefined ${wl}suppress' ;;
-    darwin*) # darwin 5.x on
-      # if running on 10.5 or later, the deployment target defaults
-      # to the OS version, if on x86, and 10.4, the deployment
-      # target defaults to 10.4. Don't you love it?
-      case ${MACOSX_DEPLOYMENT_TARGET-10.0},$host in
-	10.0,*86*-darwin8*|10.0,*-darwin[91]*)
-	  _lt_dar_allow_undefined='${wl}-undefined ${wl}dynamic_lookup' ;;
+    *-darwin*)
+      # darwin 5.x (macOS 10.1) onwards we only need to adjust when the
+      # deployment target is forced to an earlier version.
+      case ${MACOSX_DEPLOYMENT_TARGET-UNSET},$host in
+	UNSET,*-darwin[89]*|UNSET,*-darwin[12][0123456789]*)
+	  ;;
 	10.[012][,.]*)
-	  _lt_dar_allow_undefined='${wl}-flat_namespace ${wl}-undefined ${wl}suppress' ;;
-	10.*)
-	  _lt_dar_allow_undefined='${wl}-undefined ${wl}dynamic_lookup' ;;
-      esac
+	  _lt_dar_allow_undefined='${wl}-flat_namespace ${wl}-undefined ${wl}suppress'
+	  ;;
+	*)
+	  ;;
+     esac
     ;;
   esac
     if test "$lt_cv_apple_cc_single_mod" = "yes"; then
@@ -11950,7 +11952,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11963 "configure"
+#line 11955 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12056,7 +12058,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12069 "configure"
+#line 12061 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
diff --git a/zlib/configure b/zlib/configure
index f489f31bc70..05c41b7e12d 100755
--- a/zlib/configure
+++ b/zlib/configure
@@ -4169,7 +4169,7 @@ case "$host" in
     case "$enable_cet" in
       auto)
 	# Check if target supports multi-byte NOPs
-	# and if assembler supports CET insn.
+	# and if compiler and assembler support CET insn.
 	cet_save_CFLAGS="$CFLAGS"
 	CFLAGS="$CFLAGS -fcf-protection"
 	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
@@ -10735,7 +10735,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10748 "configure"
+#line 10738 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -10841,7 +10841,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10854 "configure"
+#line 10844 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H